Cortical processing of visual information during alert and non-alert brain states

描述（由申请人提供）：拟议的工作旨在了解警觉和非警觉受试者的早期视觉皮层机制。由于控制眼睛位置的行为方法的发展，在理解警觉、注意力集中的受试者的视觉感知的中枢机制方面取得了巨大进展。然而，人们对大脑皮层在警觉性下降时发挥作用的机制知之甚少。清醒的非警觉状态不等同于麻醉或睡眠状态。当不警觉时，我们能够感知，但我们的感知能力不同。人们普遍认为，当我们不警觉时，“意外就会发生”，但早期丘脑或视觉皮层机制在多大程度上对此负责（与高级认知过程相反）是一个悬而未决的问题。这个提议依赖于一个非常适合解决这个问题的独特模型系统：清醒的，不行为的兔子，一种“内在精神生活”在警觉和非警觉状态之间透明转换的动物，稳定的眼睛和羞怯的本性使其成为这些实验的理想对象。拟议的研究将检查清醒受试者大脑状态的变化，以及与之相关的反应增益的巨大变化，如何影响视觉丘脑皮层和皮层内网络中发生的信息处理的多个连续阶段。我们将研究视觉反应特性，研究机制，并开发一个生物学上的现实模型，来研究皮层输入层（第4层）的兴奋性和抑制性神经元如何对状态变化做出反应，并将研究状态修改后的视觉信息如何通过视觉皮层的输出通路传递到后续的处理站。这项工作将导致更好地了解在一个动态的，清醒的大脑视觉处理的皮质机制。从健康的角度来看，这些研究将对我们理解警觉性/警惕性缺陷如何影响视觉感知和表现产生重要影响，并将为未来人类心理健康和行为障碍的临床研究提供基础。公共卫生相关性目前的工作将对我们理解警觉性/警惕性缺陷如何影响视觉感知和表现产生重要影响。丘脑皮质系统内反应增益的中断与涉及感觉处理和警觉水平变化的精神疾病有关。该建议将揭示调节视觉丘脑皮质系统内的反应增益的机制，并通过这样做，它将为未来人类心理健康和行为障碍的临床研究提供基础。

DESCRIPTION (provided by applicant): The proposed work aims to understand early cortical mechanisms of vision in alert and in non-alert subjects. Thanks to the development of behavioral methods for the control of eye position, great advances have been made in understanding central mechanisms of visual perception of alert, attentive subjects. However, there is little understanding of cortical processes that come into play when alertness wanes. The awake, non-alert state is not equivalent to anesthesia, or to sleep states. When non-alert, we are capable of perception, but our perceptual capacities differ. It is commonly believed that "accidents happen" when we are not alert, but the extent to which early thalamic or visual cortical mechanisms may be responsible for this (as opposed to higher cognitive processes) is an open question. This proposal relies on a unique model system that is very well-suited to address this question: the awake, non-behaving rabbit, an animal who's "inner mental life" transparently shifts between alert and non-alert states, and who's stable eyes and diffident nature make it an ideal subject for these experiments. The proposed research will examine how changes in the brain state of awake subjects, and the dramatic changes in response gain that are associated with them, influence the multiple, sequential stages of information processing that occur within the visual thalamocortical and intracortical network. We will examine visual response properties, examine mechanisms, and develop a biologically realistic model of how excitatory and inhibitory neurons of the input layer of the cortex (layer 4) respond to state-changes, and will examine how state-modified visual information is conveyed by output pathways of visual cortex to subsequent processing stations. This work will lead to a better understanding of cortical mechanisms of visual processing in a dynamic, awake brain. From a health perspective, these studies will have an important impact on our understanding of how alertness/vigilance deficits can impact visual perception and performance, and will provide the basis for future clinical studies of human mental health and behavioral disorders. PUBLIC HEALTH RELEVANCE The current work will have an important impact on our understanding of how alertness/vigilance deficits can impact visual perception and performance. A disruption in response gain within thalamocortical systems has been associated with mental diseases that involve changes in sensory processing and the level of vigilance. This proposal will reveal the mechanisms that modulate response gain within the visual thalamocortical system and, by doing so, it will provide the basis for future clinical studies of human mental health and behavioral disorders.